The Ecological Forces Shaping Rainbow trout Gut Microbes and Their Role In Nutrition

Aquaculture is the fastest growing agricultural sector. The percent contribution of aquaculture to world total fisheries production exceeds that from the capture fisheries. Rainbow trout is an important aquaculture species for food, fish products as well as for recreational purposes. In order to meet the demand of aquaculture for quality feed, research was heightened on alternative protein sources. However, low digestibility resulting from antinutritional factors and imbalance amino acids in plant proteins limit their use in aquafeed industry, especially in carnivorous species like rainbow trout.

Climatic changes resulting from elevated atmospheric carbon are predicted to increase spring water temperatures of about 1-3 degrees C and increase hydraulic residence time; spring water being the main water source for rainbow trout aquaculture. Temperatures above 15 degrees C are known metabolic stressors of rainbow trout affecting nutrient utilization. However, it is not clear how specific nutrients are altered in fishes when temperature increases. Further, increased hydraulic residence times and higher culture temperatures will affect water biomass and potentially impact the gut microbiome of rainbow trout.

To address this challenge, we will develop fish diets to mitigate metabolic perturbations, minimize waste output and reduce environmental contamination. This project will develop mitigation strategies that will alleviate associated health and environmental problems. Our team is looking at providing ‘the ideal microbial composition’ for culture rainbow trout.

This collaborative project with USFWS looks at metagenomics analysis of cultured rainbow trout in different culturing environments. We are also surveying wild population of rainbow trout in different rivers of Montana to provide a wild comparison for our work.

View a presentation on this research here: Washington DC 2015.

For more information contact Lola Betiku


Related Publications

Betiku OC, Yeoman CJ, Gaylord TG, Americus B, Olivo S, Duff GC, Sealey W. 2018. Water system is a controlling variable modulating bacterial diversity of gastrointestinal tract and performance in Rainbow trout. PLoS One. 13: e0195967. DOI:

Betiku OC, Yeoman CJ, Gaylord TG, Duff GC, Hamerly T, Bothner B, Block SS, Sealey WM. 2017. Differences in Amino Acid Catabolism by Gut Microbes with/without Prebiotics Inclusion in GDDY-based Diet Affect Feed Utilization in Rainbow Trout. Aquaculture. 490: 108 – 119. DOI: 10.1016/j.aquaculture.2017.09.006

Ham BR, Barrows FT, Huttinger A, Duff GC, Yeoman CJ, Maskill MG, Sealey WM. 2015. Evaluation of dietary soy sensitivity in snake river cutthroat trout. N. Am. J. Aquaculture 77: 195-205

Ham BR, Myrick CA, Barrows FT, Yeoman CJ, Duff GC, Maskill MG, Sealey WM. 2015. Feed characteristics alter growth efficiency of cutthroat trout. J. Fish Wildlife Mgmt. 6: e1944-687